Additional Commands Required by Certain HD47780-compatible Controller

[assen@…]

I was playing recently with a DYI LCD panel based on Ampire's AC-204BYILY-H 20x4 LC display, which claims to be HD47780-compatible (full datasheet here: http://home.comet.bg/datasheets/LCD/AC-204B.pdf)

lcd4linux is latest RC2 version. Initially I noticed that no characters appeared on the display. Playing with timings did not help. After some trial and error I found that lcd4linux needs to execute one additional command in order to push the data to the display. In file drv_HD44780.c around line 445 after:

if (UseBusy) udelay(delay);

I added:

drv_generic_parport_control(SIGNAL_RS | SIGNAL_RW | SIGNAL_ENABLE | SIGNAL_ENABLE2 | SIGNAL_ENABLE3 | SIGNAL_ENABLE4 | SIGNAL_BACKLIGHT | SIGNAL_GPO, 0);

I also had to use "UseBusy? 1", otherwise only the first letter appeared on the screen. My LCD panel uses Winamp-style wiring and I have proper "wire" section in lcd4linux.conf. I'm attaching the wiring for reference.

Assen Totin

[michael]

What you are doing here is lowering *all* control lines. I'm quite sure that this is a wiring misconfiguration.

Could you please post the output of 'lcd4linux -Fvv' and your lcd4linux.conf? I will check if your config matches your wiring diagram.